Another situation to watch out for is indoor studio shooting against a white background. Often the illumination and exposure is adjusted to make the background 100% white in such situations, and you wind up basically reproducing my torture test:

A third scenario to watch for is shooting in the IR, where again the lens coatings lose their efficiency and any hotspotting inherent in the optics will become much more visible:

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Brian Caldwell

They look more like blobs than spots! Very noticeable indeed.

OT, Brian, I notice Metabones will be releasing an EF-MFT speedbooster soon, which will support lens IS. Will there be any optical performance differences between it and the Nikon-MFT booster?